DIFFERENTIAL DIAGNOSIS I 23 



(i). Animal inoculation. Male guinea-pigs should be 

 used. The material for inoculation usually consists of the 

 nasal discharge from the suspected glandered horse, bits of 

 scrapings from the ulcers, or pieces of other diseased tissue. 

 The method to be followed is precisely the same as with the 

 subcutaneous inoculation of tuberculous material. In these 

 cases there is liable to be a local swelling and abscess. The 

 first symptom of glanders noticed is usually orchitis. The 

 lymphatic glands in the groin are also enlarged. After the 

 orchitis becomes well advanced, the guinea-pig may be chloro- 

 formed and examined. Pure cultures of the specific organism 

 can be obtained in most cases from the suppurating foci in 

 the testicle. The spleen is usually enlarged and sprinkled 

 with grayish nodules. Other organs may be involved. 



(2) Mallein. Mallein is prepared in the same way as tuber- 

 culin. It consists of the glycerinated bouillon in which the 

 glanders bacteria have grown and in which are the products 

 resulting from their multiplication. It has a somewhat foetid 

 odor. In applying the mallein test the horse is injected usually 

 in the neck with the required amount (0.5 to 2 cc.) of mallein, 

 the quantity depending upon the extent of concentration. If a 

 concentrated mallein is used it should be diluted with a i per 

 cent carbolic acid solution to at least 2 cc. The reaction is as 

 follows. In a few hours there forms at the place of injection 

 a hot, inflammatory swelling. It i.s very painful and incase 

 of glanders quite large. From all sides of the swelling there 

 may radiate wavy lines consisting of swollen lymphatics, hot 

 and painful when touched, extending toward the adjoining 

 glands. When the mallein injection is made aseptically, this 

 swelling never suppurates, but it increases in size during a 

 period of from 24 to 36 hours and persists for several days 

 when it gradually diminishes and finally disappears at the end 

 of eight or ten days. With the appearance of the local swell- 

 ing the patient becomes dull and dejected, the eyes have an 

 anxious expression, the coat islusterless, the flanks contracted, 

 the respiration hurried, the appetite is impaired, frequent 

 shudders are observed to pass through the muscles of the fore 

 legs and sometimes the trunk is subject to violent convulsive 



